Telescopic tunnel form

ABSTRACT

The invention relates to a tunnel form comprising:  
     two vertical forming walls ( 2 ) joined by a horizontal wall ( 3 ) in two parts ( 3 A),  
     at the base of the form, means for adjusting the height of the position of the top edge ( 5 ) of the tunnel form relative to the reference surface ( 6 ), and means of support ( 7 ) at least indirectly with the reference surface so that it can be extracted from the tunnel after production.  
     This tunnel form is characterized in that the aforementioned height adjusting means ( 4 ) are supported by props ( 9 ), each slide-mounted in a sleeve ( 10 ) attached to the base of the tunnel form.

[0001] The invention relates to a tunnel form.

[0002] It also relates to the utilization of the tunnel form, particularly the method for stripping said tunnel form.

[0003] For the construction of concrete buildings, it is standard to pour the lateral walls at the same time that the upper slab is poured.

[0004] The tunnel or tunnels thus produced are then fitted with separating walls that are non-load bearing in order to delimit apartments.

[0005] For this purpose, forms known as tunnel forms are used.

[0006] This form exists in the form of two vertical forming walls joined at their top parts by a horizontal forming wall so that the assembly forms an upside down U.

[0007] A brace maintains the geometry of the form, and adjusting means make it possible to adjust the height of the form and the verticality.

[0008] Normally, the vertical forming walls have a height slightly lower than the desired height between the floor and the ceiling, in order to allow stripping.

[0009] Extending from a lower slab called a reference surface, in line with the positions of the vertical walls, a kicker of relatively low height, on the order of ten centimeters at most, is produced, making it possible to position the base of the vertical forming walls of the tunnel form and to close the interstice that exists between the base of the vertical forming wall and the reference surface on which the tunnel form rests.

[0010] This kicker is produced by placing L-shaped parts at the top part of the tunnel form.

[0011] The slight difference between the height of the forming wall and the distance between the floor and the ceiling makes it possible to strip the tunnel and extract it after having acted on the height adjusting means.

[0012] Generally, after the form is put in position on both sides of the walls to be produced, concrete is poured in order to fill in the vertical spaces delimited by the forming walls and to form the top slab which, when it solidifies, will constitute the reference surface for a higher floor.

[0013] After the concrete of the vertical walls and the top slab are hard enough, the tunnel forms are stripped.

[0014] To do this, by acting on the technical elements that maintain the geometry of the upside-down U, the top forming wall is detached from the top slab produced, and also, by acting on the height adjusting means, the top of the tunnel form is lowered by several centimeters and then extracted by being rolled away.

[0015] These height adjusting means are limited to an amplitude of a few centimeters.

[0016] For some time, architects have maintained the practice of constructing buildings with height differences among the stories and hence having different floor/ceiling heights.

[0017] Builders must therefore use tunnel forms wherein the size of the vertical walls is adapted to the height of each story of the building.

[0018] This increase in the number of forms obviously creates excess costs, since the forms cannot be used full-time.

[0019] Moreover, due to cost concerns, it is not possible to use very many forms of different heights.

[0020] There are existing forms that make it possible to adapt the height of the vertical forming wall.

[0021] In order to do this, the vertical wall is in two parts, a bottom part of predetermined height and a top part used for the adjustment, and it is this top part to which the horizontal wall is attached.

[0022] The set-up/takedown times are prohibitive.

[0023] The object of the invention is specifically to eliminate this drawback.

[0024] To this end, the subject of the invention is a tunnel form comprising:

[0025] two vertical forming walls joined by a horizontal wall in two parts assembled with fastening means,

[0026] at the base of the form, means for adjusting the height of the position of the top edge of the tunnel form relative to the reference surface, and means of support at least indirectly with the reference surface so that it can be extracted from the tunnel after the production of said tunnel,

[0027] this form being characterized in that the aforementioned height adjusting means are supported by props, each slide-mounted in a sleeve attached to the base of the tunnel form.

[0028] Another subject of the invention is the utilization of the tunnel form, and particularly the method for stripping said tunnel form

[0029] The invention will be clearly understood with the help of the description below, given as a non-limiting example in reference to the attached drawing, which schematically represents:

[0030]FIG. 1: a form according to the invention,

[0031]FIGS. 2 through 9: the form in various stages of utilization

[0032]FIGS. 10 through 13: various details.

[0033] Referring to the drawing, we see a tunnel form 1.

[0034] Only half of a tunnel form is represented.

[0035] Conventionally, this tunnel form 1 comprises:

[0036] two vertical forming walls 2 joined by a horizontal wall 3 in two parts 3A,

[0037] at the base of the form, means 4 for adjusting the height of the position of the top edge 5 of the tunnel form relative to the reference surface 6, and means 7 of support at least indirectly with the reference surface so that it can be extracted from the tunnel after production.

[0038] These height adjusting means 4 have a relatively small amplitude of adjustment, on the order of ten to twenty centimeters.

[0039] A brace 8 mounted on the back of the forming panels makes it possible to adjust the geometry of the upside down U and to support the loads that are exerted on the various forming panels when the concrete is poured.

[0040] The means 7 of support at least indirectly with the reference surface so that it can be extracted from the tunnel after production are constituted by wheels 7A or a sliding surface 7B cooperating with rollers mounted on the reference surface.

[0041] The form is conventionally extracted by rolling the form in a direction perpendicular to the section defined by the upside down U.

[0042] The two parts of the horizontal wall are joined by fastening means (not represented).

[0043] These forming walls are constituted by a forming panel reinforced on its rear surface by stiffeners.

[0044] According to the invention, the aforementioned height adjusting means 4 are supported by props 9, each slide-mounted in a sleeve 10 attached to the base of the tunnel form.

[0045] In the forming position, the height adjusting means 4 are thus far away from the bottom edge 11 of the vertical forming wall and also from the support means 7.

[0046] During the utilization of this form, it is necessary to use a kicker 12 that is relatively high and that fills the space between the bottom of the form and the reference surface.

[0047] The height of this kicker is, for example, on the order of one hundred to one thousand five hundred millimeters.

[0048] This kicker is produced ahead of time.

[0049] Props 9 are provided on the back of the vertical forming wall and at the level of the triangulation.

[0050] Pins 13 make it possible to position the bottom edge of the form relative to the reference surface at a regular pitch.

[0051] These pins therefore pass through both the sleeve and the prop.

[0052] There are means for step-by-step adjustment of the props.

[0053] The prop is provided at its base with height adjusting means 4.

[0054] For example, this could be bolt 4A that engages with a threading 4B formed in the base of the prop.

[0055] This threading is for example borne by a nut installed in the tubular part of the prop.

[0056] The base of this bolt 4A is joined to a sole plate 4C by a vertical pin 4D.

[0057] The sleeve 10 can be mounted on the form permanently, but it can also be attached with removable fastening means 14.

[0058]FIGS. 12 and 13 represent the detachable joint of the sleeve with the triangulation.

[0059] The sleeve is borne by a U-shaped section 15 that covers an element of the triangulation.

[0060] Bolts provide the fastening.

[0061]FIG. 10 represents the fastening of the sleeve mounted on a vertical stiffener of the vertical forming wall.

[0062] Bolts maintain the joint with the stiffener.

[0063] Advantageously, for the stripping, the horizontal forming wall has means 19 for attaching at least one sling 20.

[0064] When using only one sling, the point of attachment is located on the vertical axis passing through the center of gravity.

[0065] Before the concrete is poured, in line with the means for attaching the sling and above these attaching means, a reserved part 17 is provided in the space that will be filled in by the concrete, so that after sufficient hardening of the concrete and shrinking of the reserved part, the sling is inserted through the space retained by the reserved part in the top slab 18 so that it then supports the tunnel form.

[0066] Thus, for stripping:

[0067] each part 3A of the horizontal forming wall is tilted (FIG. 5),

[0068] the sling is attached to the horizontal forming wall (FIG. 6),

[0069] the form is supported,

[0070] the props are raised so that the base of these props is at a level located above the level of the support means (FIG. 7),

[0071] the tunnel form is lowered until these support means are in contact with the reference surface (FIG. 8),

[0072] the slings are removed (FIG. 9) and

[0073] the form is then moved conventionally by sliding.

[0074] The use of slings attached to a crane prevents the weight of the tunnel form from being supported by the top slab, which has hardened but is not yet capable of supporting a weight greater than its own weight.

[0075] The props allow for a rough adjustment, for example every fifteen centimeters, the final adjustment being obtained by means of screw jacks 4.

[0076] These props are attached to the tunnel form by removable fastening means such as bolts, so that these props can be easily installed or removed without changing the tunnel base.

[0077] The advantage is that it is possible to produce, with the same form, all of a building's stories of normal or non-normal height. 

1. Tunnel form comprising: two vertical forming walls joined by a horizontal wall (3) in two parts (3A), at the base of the form, means (4) for adjusting the height of the position of the top edge (5) of the tunnel form relative to the reference surface (6), and means of support (7) at least indirectly with the reference surface so that it can be extracted from the tunnel after production, this tunnel form being characterized in that the aforementioned height adjusting means (4) are supported by props (9), each slide mounted in a sleeve (10) attached to the base of the tunnel form.
 2. Tunnel form according to claim 1, characterized in that props (9) are provided on the back of the vertical forming wall and at the level of the triangulation.
 3. Tunnel form according to claim 1 or 2, characterized in that: the prop is provided at its base with height adjusting means (4), the adjusting means consist in a bolt (4A) that engages with a threading (4B) formed in the base of the prop, this threading being borne by a nut installed in the tubular part of the prop.
 4. Tunnel form according to claim 5, characterized in that the sleeve is borne by a U-shaped section (15) that covers an element of the triangulation.
 5. Tunnel form according to claim 1, characterized in that the props are joined to with the form by removable fastening means.
 6. Tunnel form according to claim 1, characterized in that the horizontal forming wall has means (19) for attaching at least one sling (20).
 7. Tunnel form according to claim 6, characterized in that when only one sling is used, the point of attachment is located on the vertical axis passing through the center of gravity.
 8. Tunnel form according to claim 1, characterized in that the form comprises means for step-by-step adjustment of the props.
 9. Utilization of a form according to any of claims 1 through 8, characterized in that before the concrete is poured, in line with the means for attaching the sling and above these attaching means, a reserved part (17) is provided in the space that is to be filled by the concrete, so that after sufficient hardening of the concrete and shrinking of the reserved part, the sling is inserted through the space retained by the reserved part in the top slab (18), so that it then supports the tunnel form or a part of it.
 10. Utilization of the form according to claim 9 characterized in that: each part (3A) of the forming wall is tilted, the sling is attached to the horizontal forming wall, the form is supported, the props are raised so that the base of these props is at a level located above the level of the support means, the tunnel form is lowered until these support means are in contact with the reference surface, the slings are removed and the form is then moved conventionally by sliding. 